Heat exchanger module and method

Abstract

Heat exchanger module (2) comprising: - a body (3) comprising at least two spiral sheets (31, 32), the sheets delimiting between them a first circulation channel (50) for a first fluid (A) and a second circulation channel (51) for a second fluid (B); and - a separator (4) for receiving the first fluid (A) capable of allowing a first fraction (A1) of the first fluid (A) to pass to another heat exchanger module located below the heat exchanger module, and of preventing a second fraction (A2) of the first fluid (A) from reaching the other heat exchanger module, the first fraction (A1) of the first fluid containing a gaseous phase, and the second fraction (A2) of the first fluid consisting of a liquid phase.

Description

DOMAINE TECHNIQUE

[0001] This disclosure relates to heat exchangers, in particular spiral heat exchangers configured to treat a liquid phase of a fluid. ETAT DE LA TECHNIQUE

[0002] A spiral heat exchanger module typically comprises a central tubular portion and a spiral body comprising at least two sheets spirally wound around the central tubular portion. The central tubular portion may be formed by a wound portion of the two sheets or by a separate tubular piece to which the two sheets are welded.

[0003] The two sheets spirally wound around the central tubular part define between them a first spiral-shaped circulation channel for the circulation of a hot fluid and a second spiral-shaped circulation channel for the circulation of a cold fluid. The circulation of the hot fluid and the cold fluid inside the spiral circulation channels allows heat exchange between the fluids.

[0004] The modules can be configured to be stacked, in a vertical direction, to obtain a multi-stage heat exchanger assembly. To achieve this, the modules each have openings at their ends configured to be mutually connected. Thus, the hot fluid can undergo several successive heat exchanges within the heat exchanger assembly.

[0005] However, in some applications, the hot fluid being treated may consist mainly of a gaseous phase, and each heat exchange results in condensation of a fraction of this gaseous phase. Thus, the proportion of liquid phase in the hot fluid increases as it passes through successive modules. However, increasing the proportion of liquid phase can make heat exchanges less efficient.

[0006] Indeed, on the one hand, part of the heat transferred between the hot fluid and the cold fluid is used to cool the liquid phase, which limits the efficiency of cooling the gas phase. On the other hand, the liquid phase may contain chemical compounds that tend to form deposits on the internal walls of the heat exchanger modules and which can, after a certain time, cause clogging of the first circulation channel. EXPOSE GENERAL

[0007] One aim of this presentation is therefore to improve the efficiency of heat exchanges within a multi-stage heat exchanger assembly.

[0008] For this purpose, according to a first aspect of the present disclosure, a heat exchanger module is proposed comprising: a body comprising at least two sheets, each sheet being spirally wound around the same main axis, the sheets including a first sheet and a second sheet delimiting between them a first circulation channel for a first fluid and a second circulation channel for a second fluid, separated from the first circulation channel, the first sheet and the second sheet having edges defining a first face of the body and a second face of the body, opposite the first face, the first face and the second face extending transversely to the main axis, the first face having first inlet openings to allow circulation of the first fluid from the outside of the body to the first circulation channel, and the second face having first outlet openings to allow circulation of the first fluid from the first circulation channel to the outside of the body;and a separator for receiving the first fluid flowing through the first outlet openings, the separator being adapted to allow a first fraction of the first fluid to pass to first inlet openings of another heat exchanger module located below the heat exchanger module, and to prevent a second fraction of the first fluid from reaching the first inlet openings of the other heat exchanger module, the first fraction of the first fluid containing a gas phase, and the second fraction of the first fluid consisting of a liquid phase. ;

[0009] Thus, the separator prevents part of the liquid phase of the first fluid, for example at least 80% of the liquid phase of the first fluid, from penetrating into the next module in the stack. The proposed solution therefore proportionally reduces the liquid phase and makes it possible to increase the efficiency of heat exchanges within the multi-stage heat exchanger.

[0010] In one possible embodiment, it may be provided that the separator comprises a passage allowing circulation of the first fraction of the first fluid towards first inlet openings of the other heat exchanger module, and a first separating wall having a first collection surface arranged to receive the first fluid from the first outlet openings, the first collection surface being oriented relative to the main axis to guide the first fraction of the first fluid by gravity while moving the second fraction of the first fluid away from the passage.

[0011] It may further be provided that the first collection surface is oriented relative to the main axis to guide the second fraction of the first fluid by gravity towards an outlet pipe for the first fluid.

[0012] Therefore, gravity can be advantageously used to prevent the liquid phase portion of the first fluid from entering the next module. Thus, no additional energy input is required for separation.

[0013] It may be provided that the first dividing wall has a conical shape, having an axis coincident with the main axis.

[0014] It may also be provided that the passage includes a passage opening located at a vertex of the cone.

[0015] The separator may be provided to comprise a second separating wall arranged to prevent the first fraction of the first fluid from the first outlet openings from reaching the passage.

[0016] It may further be provided that the second partition wall extends around the main axis.

[0017] It may also be provided that the second partition wall has a second collection surface oriented relative to the main axis to guide the first fraction of the first fluid by gravity towards the first collection surface.

[0018] Thus, heat exchanges are further improved by separating more liquids from the first fluid.

[0019] It may be provided that the second dividing wall has a conical shape, having an axis coincident with the main axis.

[0020] The heat exchanger module may be provided with an inlet pipe for injecting the second fluid from outside the body into the second circulation channel and a first outlet pipe for discharging the second fluid from the second circulation channel to outside the body.

[0021] This makes it possible to evacuate the liquid phase portion from the module. Evacuation also allows the liquid phase portion to be used, for example by recirculating it within the module after heating it.

[0022] The module may be provided to include a nozzle for spraying a cleaning agent into the first fluid at the location where the first fluid enters the first circulation channel via the first inlet openings.

[0023] Thus, the cleaning product helps to reduce the risk of clogging the first circulation channel in which the first fluid circulates and to further improve thermal exchanges.

[0024] According to a second aspect of the present disclosure, there is provided a heat exchanger assembly, comprising at least two heat exchanger modules according to the first aspect, the heat exchanger modules being connected together, such that the first fraction of the first fluid containing the gas phase from one heat exchanger module of the heat exchanger assembly enters the first circulation channel via the first inlet openings of the body of another heat exchanger module of the heat exchanger assembly.

[0025] It may be provided that each heat exchanger module comprises nozzles for spraying a cleaning agent into the first fluid at the location where the first fluid enters the first circulation channel via the first inlet openings, the heat exchanger assembly comprising a control unit configured to control a flow rate and / or a temperature of the cleaning agent sprayed by each nozzle of each heat exchanger module as a function of a difference between a pressure of the first fluid at the outlet of the first outlet openings and a pressure of the first fluid at the inlet of the first inlet openings of the body of the heat exchanger module.

[0026] The cleaning product can therefore be injected as soon as the heat exchange decreases in the module, which saves cleaning product.

[0027] According to a third aspect of the present disclosure, there is provided a method of treating a first fluid, comprising steps of: circulating the first fluid in a first circulation channel of a body of a first heat exchanger module according to the first aspect, separating the first fluid flowing through the first outlet openings of the body of the first heat exchanger module into a first fraction of the first fluid containing a gas phase, and a second fraction of the first fluid consisting of a liquid phase, discharging the second fraction of the first fluid, and injecting the first fraction of the first fluid into a first circulation channel of a body of a second heat exchanger module.

[0028] It may be provided that the second heat exchanger module is in accordance with the first aspect. DESCRIPTION DES FIGURES

[0029] Other features, aims and advantages will emerge from the following description, which is purely illustrative and not limiting, and which must be read in conjunction with the attached drawings in which: there figure 1 and the figure 2 illustrate heat exchanger assemblies; the figure 3 schematically illustrates a top sectional view of an exemplary heat exchanger module; figure 4 schematically illustrates a sectional front view of a heat exchanger module; and the figure 5 is a flowchart of a method of implementing a fluid treatment process. DESCRIPTION DETAILLEE

[0030] A heat exchanger assembly 1, also called a stage exchanger, is illustrated in the figures 1 And 2. The heat exchanger assembly 1 is several meters high, for example 4 meters, and has a floor area of ​​several square meters, for example 5 m 2 < . The heat exchanger assembly 1 has a mass of several hundred tons, for example 350 tons.

[0031] In normal use, the heat exchanger assembly 1 is vertical. The heat exchanger assembly 1 comprises a plurality of heat exchanger modules 2a, 2b, 2c stacked and fixedly connected to each other. In the example illustrated in figures 1 And 2, the heat exchanger assembly 1 comprises three heat exchanger modules 2a, 2b, 2c. Of course, the exchanger assembly 1 may comprise more than three modules or fewer than three modules. In this example, the modules are cylindrical in shape, but they may also be cubic, elliptical or any other shape suitable for manufacturing from sheet metal assemblies or by casting. A first inlet pipe 5 communicates with an upper end of the heat exchanger assembly 1 and a first outlet pipe 7, opposite the inlet pipe 5, communicates with a lower end of the heat exchanger assembly 1. Each heat exchanger module 2a, 2b, 2c comprises a respective inlet pipe 6a, 6b, 6c and a respective outlet pipe 8a, 8b, 8c. Each heat exchanger module 2a, 2b, 2c may also comprise several inlet pipes and / or several outlet pipes.Connections 9a, 9c between inlet pipes and outlet pipes are configured to mutually connect the heat exchanger modules. The heat exchanger assembly 1 is configured to carry out a heat exchange between a first fluid A and a second fluid B in each heat exchanger module 2a, 2b, 2c. In operation, a first fluid A, for example a hot fluid to be cooled, enters the exchanger assembly 1 through the inlet pipe 5, at the upper level of the heat exchanger assembly, and leaves the heat exchanger assembly 1 through the outlet pipe 7, at the lower level of the heat exchanger assembly 1. Thus, the first fluid A flows by gravity into the heat exchanger assembly 1, circulating successively in each heat exchanger module 2a, 2b, 2c.In each heat exchanger module 2a, 2b, 2c, the first fluid exchanges heat with a second fluid B, for example a refrigerant, which circulates through the heat exchanger assembly 1 via the inlet 6a, 6b, 6c and outlet 8a, 8b, 8c pipes of each module 2a, 2b, 2c.

[0032] An example of heat exchanger module 2 is illustrated in the figures 3 And 4. The heat exchanger module 2 comprises a body 3 in which the first fluid A and the second fluid B can circulate to carry out a heat exchange between the first fluid A and the second fluid B. The body 3 comprises four sheets 31, 32, 33, 34. The sheets 31, 32, 33, 34 are wound in a spiral around the same main axis X, the sheets delimiting between them a first circulation channel 50 and a second circulation channel 51. The exchanger module 3 is configured to circulate the first fluid A longitudinally with respect to the main axis X through the first circulation channel 50. To do this, a first face of the body and a second face of the body opposite the first face are defined by an edge 310, 311 of each sheet 31, 32, 33, 34.The first face has inlet openings 24 to allow circulation of the first fluid A from the outside of the body 3 to the first circulation channel 50, and the second face has outlet openings 25 to allow circulation of the first fluid A from the first circulation channel 50 to the outside of the body 3. Thus, the first fluid A enters the body 3 through the inlet openings 24 then circulates in the first channel 50 delimited by the second and third sheets 32, 33 as well as the fourth and first sheets 34, 31 until reaching the outlet openings 25. The heat exchanger module 2 is further configured to allow circulation of the second fluid B between the inlet pipe 6 and the outlet pipe 8. The second circulation channel 51 is spiral-shaped.Thus, the second fluid B enters the body 3 through the inlet pipe 6 and circulates a first time in a spiral towards the inside of the body 3 in the second channel 51 delimited by the first sheet 31 and the second sheet 32 ​​to converge up to the main axis X then, it circulates a second time in a spiral towards the outside of the body 3 still in the second channel 51 delimited this time by the third sheet 33 and the fourth sheet 34 in order to move away from the main axis X until reaching the outlet pipe 8. Consequently, during the circulation of the two fluids A, B in the two channels 50, 51, a heat exchange takes place between the first fluid A and the second fluid B, through the sheets 31, 32, 33, 44.

[0033] Of course, the body 3 can comprise other sets of sheets, for example three sheets or two sheets, a number of sheets being limited to at least two in order to be able to delimit the first channel 50 and the second channel 51.

[0034] The heat exchanger module 2 further comprises a separator 4 configured to separate a liquid phase from a gaseous phase of the first fluid A at the outlet of the heat exchanger module 2. On the one hand, the separator 4 is capable of allowing a first fraction A1 of the first fluid A, predominantly in the gaseous phase, to pass towards inlet openings of another exchanger module located below the exchanger module in the stack and, on the other hand, of preventing a second fraction A2, consisting of a liquid phase, from reaching the first inlet openings of the other heat exchanger module.

[0035] An example of separator 4 is shown in figure 4 . When the heat exchanger module 2 is in normal operation, the separator 4 is located below the outlet openings 25. The separator 4 comprises a first wall 41 and a second wall 42 located above the first wall 41. The first wall 41 and the second wall 42 are each conical in shape, having as their axis the main axis X. The walls 41, 42 may also be inclined planes or any other surface inclined relative to the main axis X. When the first fluid A passes through the separator 4, a first portion of the second fraction A2 is collected directly by the first wall 41 (without flowing over the second wall 42) and a second portion of the second fraction A2 is collected by the second wall 42 and is then guided by the second wall 42 towards the first wall 41. Thus, the second fraction A2 consisting of a liquid phase is recovered by the first wall 41 which forms a recovery surface for the liquid phase.The first wall 41 and the second wall 42 are inclined relative to the main axis X, so that when the axis X is positioned vertically (in normal use), the first wall 41 and the second wall 42 guide the second fraction A2 of the first fluid A by gravity away from the main axis X.

[0036] The first wall 41 further comprises a passage opening 43, through which the first fraction A1, which is predominantly in the gas phase of the first fluid A, can flow. In the example illustrated in the figure 4 , the passage opening 43 is located at the top of the cone formed by the first wall 41. The second wall 42 is located above the first wall 41 while being arranged at a distance from the first wall 41. The first part of the second fraction A2 is guided by the first wall 41 and by the second wall 42 to prevent it from flowing through the passage opening 43 to the heat exchanger module located below. The second wall 42 extends above the passage opening 43, so as to prevent the second part of the second fraction A2 from flowing through the passage opening 43 by guiding it towards the first wall 41.The separator 4 thus makes it possible to block the second fraction A2 consisting of a liquid phase while allowing the first fraction A1 comprising the gaseous phase to pass because, when the first and second fractions A1, A2 flow by gravity into the heat exchanger module 2, the second fraction A2 consisting of a liquid phase is retained by the first recovery wall 41 while the first fraction A1, which is predominantly in the gaseous phase, is directed towards another heat exchanger module 2. To evacuate the second fraction A2 retained by the first wall 41 from the heat exchanger module 2, the heat exchanger module 2 may further comprise other evacuation pipes 12 communicating with the second surface, as illustrated for example in . figures 1 , 2 And 3 , or connected to the second surface.

[0037] On the figure 4 , the heat exchanger module 2 comprises four nozzles 10 arranged close to where the first fluid A enters the first circulation channel A via the inlet openings 24. Of course, the heat exchanger module 2 may comprise a single nozzle, fewer than four nozzles or more than four nozzles. The nozzles 10 are configured to spray a cleaning product, in liquid form, into the flow of the first fluid A, in order to clean the sheets and prevent components of the first fluid, such as naphthalene for example, from being deposited on the sheets. The cleaning product may for example be a mixture of water and tar, more commonly called "tare", which has the effect of detaching the naphthalene from the sheets. The naphthalene and the cleaning product flow by trickling until they reach the outlet opening 25.The cleaning product and the naphthalene which flow in liquid form from the outlet openings 25 are part of the second fraction A2 which is recovered by the separator 4. Thus, the first fluid A is cleaner at the outlet of each exchanger module 2 which has the effect of limiting the risks of clogging in a heat exchanger module 2. Each heat exchanger module 2 of the heat exchanger assembly 1 may comprise a set of nozzles 10 for spraying cleaning product into the first fluid A at the inlet of the heat exchanger module 2. In variants, only one heat exchanger module 2 may comprise a set of nozzles 10 or several heat exchanger modules 2 may comprise a set of nozzles 10. The set of nozzles 10 may further be supplied via supply pipes 11 (. figure 2 ).

[0038] It may be provided that the heat exchanger assembly 1 comprises a control unit configured to control a flow rate and / or a temperature of the cleaning product sprayed by each set of nozzles 10. The control unit may control a flow rate and / or a temperature of the cleaning product sprayed by each nozzle of each heat exchanger module 2. It may be provided that the control unit can control a flow rate and / or a temperature of the cleaning product sprayed by a nozzle of each heat exchanger module 2 or of a heat exchanger module 2, or of each module of a plurality of heat exchanger modules. It may also be provided that the control unit can control a flow rate and / or a temperature of the cleaning product sprayed by a plurality of nozzles of each heat exchanger module 2, or of a heat exchanger module 2, or of each module of a plurality of modules.The control unit may further control a flow rate and / or a temperature of the cleaning product as a function of a difference between a pressure of the first fluid A at the outlet of the outlet openings 25 and a pressure of the first fluid A at the inlet of the inlet openings 24 of the body 3 of the heat exchanger module 2. The control unit may also control the flow rate and / or the temperature of the cleaning product as a function of a minimum, a maximum or an average of a difference between a pressure of the first fluid A at the outlet of the outlet openings 25 and a pressure of the first fluid A at the inlet of the inlet openings 24 of the body 3 in each heat exchanger module 2, or in each module of a plurality of modules.

[0039] Thus, the heat exchanger assembly 1 is capable of implementing a method for treating the first fluid A, in which, with reference to the figure 5 , the following steps are implemented.

[0040] During a step E1, the first fluid A circulates in the first circulation channel 50 of the body of a first heat exchanger module 2a.

[0041] During a step E2, the first fraction A1 of the first fluid A flowing through the first outlet openings 25 of the body 3, mainly in the gas phase, is separated from the second fraction A2 of the first fluid A, consisting of a liquid phase, by the separator 4.

[0042] During a step E3, the second fraction A2 of the first fluid A is evacuated, for example from the first heat exchanger module 2a.

[0043] During a step E4, the first fraction A1 of the first fluid A is injected into a first circulation channel 50 of a body 3 of a second heat exchanger module 2b.

[0044] Many modifications can be made to the heat exchanger assembly, the heat exchanger module and the process without departing from the scope of the presentation.

Claims

1. Heat exchanger module (2) comprising: - a body (3) comprising at least two sheets (31, 32), each sheet (31, 32) being spirally wound around the same main axis (X), the sheets including a first sheet (31) and a second sheet (32) delimiting between them a first circulation channel (50) for a first fluid (A) and a second circulation channel (51) for a second fluid (B), separated from the first circulation channel (50), the first sheet (31) and the second sheet (32) having edges (310, 311) defining a first face of the body (3) and a second face of the body (3), opposite the first face, the first face and the second face extending transversely to the main axis (X), the first face having first inlet openings (24) to allow circulation of the first fluid (A) from outside the body (3) to the first channel of circulation (50),and the second face having first outlet openings (25) to allow circulation of the first fluid (A) from the first circulation channel (50) to the outside of the body (3); and - a separator (4) to receive the first fluid (A) flowing through the first outlet openings (25), the separator (4) being able to allow a first fraction (A1) of the first fluid (A) to pass towards first inlet openings of another heat exchanger module located below the heat exchanger module, and to prevent a second fraction (A2) of the first fluid (A) from reaching the first inlet openings of the other heat exchanger module, the first fraction (A1) of the first fluid containing a gaseous phase, and the second fraction (A2) of the first fluid consisting of a liquid phase., 2. Heat exchanger module (2) according to claim 1, wherein the separator (4) comprises a passage allowing circulation of the first fraction of the first fluid towards first inlet openings of the other heat exchanger module, and a first separating wall (41) having a first collection surface arranged to receive the first fluid (A) from the first outlet openings (25), the first collection surface being oriented relative to the main axis (X) to guide the first fraction (A1) of the first fluid (A) by gravity while moving the second fraction (A2) of the first fluid (A) away from the passage.

3. Heat exchanger module (2) according to claim 2, wherein the first collection surface is oriented relative to the main axis (X) to guide the second fraction (A2) of the first fluid (A) by gravity towards an outlet pipe for the first fluid. ​4. Heat exchanger module according to one of claims 2 or 3, in which the first separating wall (41) has a conical shape, having an axis coincident with the main axis (X).

5. Heat exchanger module according to claim 4, wherein the passage comprises a passage opening (43) located at an apex of the cone.

6. Heat exchanger module according to one of claims 2 to 5, wherein the separator (4) comprises a second separation wall (42) arranged to prevent the first fraction (A1) of the first fluid (A) coming from the first outlet openings (25) from reaching the passage.

7. Heat exchanger module according to claim 6, wherein the second separating wall (42) has a second collection surface oriented relative to the main axis (X) to guide the first fraction (A1) of the first fluid (A) by gravity towards the first collection surface.

8. Module according to one of claims 6 or 7, in which the second separating wall (42) has a conical shape, having an axis coincident with the main axis (X).

9. Heat exchanger module according to one of claims 1 to 8, comprising an inlet pipe (6) for injecting the second fluid (B) from outside the body into the second circulation channel (51) and a first outlet pipe (8) for discharging the second fluid (B) from the second circulation channel (51) to the outside of the body (3).

10. Heat exchanger module according to one of claims 1 to 9, comprising a nozzle (10) for spraying a cleaning agent into the first fluid (A) at the location where the first fluid (A) enters the first circulation channel (50) via the first inlet openings (24).

11. Heat exchanger assembly (1), comprising at least two heat exchanger modules (2a, 2b) according to one of claims 1 to 10, the heat exchanger modules (2a, 2b) being connected to each other, so that the first fraction (A1) of the first fluid (A) containing the gas phase coming from a heat exchanger module (2a) of the heat exchanger assembly (1) enters the first circulation channel (50) via the first inlet openings (24) of the body (3) of another heat exchanger module (2b) of the heat exchanger assembly (1).

12. The heat exchanger assembly (1) of claim 11, wherein each heat exchanger module (2a, 2b) comprises nozzles (10) for spraying a cleaning agent into the first fluid (A) at the location where the first fluid (A) enters the first circulation channel (50) via the first inlet openings (24), the heat exchanger assembly (1) comprising a control unit configured to control a flow rate and / or a temperature of the cleaning agent sprayed by each nozzle (10) of each heat exchanger module (2a, 2b) as a function of a difference between a pressure of the first fluid (A) at the outlet of the first outlet openings (25) and a pressure of the first fluid (A) at the inlet of the first inlet openings (24) of the body of the heat exchanger module. ​13. A method for treating a first fluid (A), comprising steps of: - circulating (E1) the first fluid (A) in a first circulation channel (50) of a body of a first heat exchanger module (2a) according to one of claims 1 to 10, - separating (E2) the first fluid (50) flowing through the first outlet openings (25) of the body of the first heat exchanger module (2a) into a first fraction (A1) of the first fluid (A) containing a gaseous phase, and into a second fraction (A2) of the first fluid (A) consisting of a liquid phase, - discharging (E3) the second fraction (A2) of the first fluid (A), and - injecting (E4) the first fraction (A1) of the first fluid (A) into a first circulation channel (50) of a body of a second heat exchanger module (2b).

14. Treatment method according to claim 13, wherein the second heat exchanger module (2b) is according to one of claims 1 to 10.

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